Patent GB-592614-A (GB)
Title: Manufacture of dyestuffs of the stilbene series
IPC: C09B56/04
Filed: 1943-07-30
Abstract: Polyazo dyestuffs of the stilbene series, containing two groupings of the general formula <FORM:0592614/IV/1> (wherein A represents an azo or azoxy group and Py a pyrazolone residue) united by at least one stilbene residue, are manufactured by: (1) tetrazotizing 1 mol. of a stilbene compound containing two diazotizable amino groups, coupling with 2 mols. of a 2-aminobenzoic acid capable of coupling in the 5-position, diazotizing the amino groups in the 2-position of the 2-aminobenzoic acid and coupling with 2 mols. of a pyrazolone; or (2) condensing 1 mol. of a stilbene compound containing two nitro groups with 2 mols. of an azo compound of the general formula <FORM:0592614/IV/2> or with 2 mols. of a 2 : 5-diaminobenzoic acid followed by tetrazotization and coupling with 2 mols. of a pyrazolone; or (3) diazotizing 1 mol. of a stilbene compound containing a nitro and a primary amino group, coupling with 1 mol. of a 2-aminobenzoic acid capable of coupling in the 5-position, again diazotizing, coupling with 1 mol. of a pyrazolone, and then condensing the nitro-disazo compound so formed with 1 mol. of an azo compound of the general formula given under (2), or with 1 mol. of a 2 : 5-diaminobenzoic acid followed by diazotization and coupling with 1 mol. of a pyrazolone; or (4) diazotizing 1 mol. of a stilbene compound containing a nitro and a primary amino group, coupling with 1 mol. of a 2-aminobenzoic acid capable of coupling in the 5-position, condensing the resulting nitromonoazo dyestuff with 1 mol. of a 2 : 5-diaminobenzoic acid, tetrazotizing the diamino compound so formed and coupling with 2 mols. of a pyrazolone; or (5) coupling a diazo compound of an amine of the general formula <FORM:0592614/IV/3> (wherein B represents a stilbene residue) with a pyrazolone, and linking the molecules of the product in pairs by reduction of their nitro groups to an azo or azoxy group; or (6) coupling 1 mol. of a tetrazo compound of a diamine of the general formula <FORM:0592614/IV/4> with 2 mols. of a pyrazolone; or (7) treating a compound of the general formula <FORM:0592614/IV/5> with phosgene.  The products may be treated in substance or on the fibre with agents yielding metal.  The stilbene compounds may contain further substituents, e.g. water-solubilizing groups such as sulphonic acid groups.  For coupling with diazo compounds of the stilbene series, the 2-aminobenzoic acids are advantageously employed in the form of their o -phonic acid group being subsequently removed by saponification.  The pyrazolone coupling components may contain an alkyl group in the 3-position, and may be unsubstituted in the 1-position or may contain therein a substituent, such as an aryl group, especially phenyl, which may also contain substituents, e.g. water-solubilizing groups such as sulphonic or carboxylic acid groups, or also the salicylic acid grouping, or groups not imparting solubility in water, such as nitro or sulphonamido groups.  The products may be used for dyeing or printing animal fibres (e.g silk and wool) and especially cellulosic fibres (e.g. cotton, linen and other vegetable fibres, p  and artificial silk and staple fibre of regenerated cellulose), and also mixed yarns and mixed fabrics.  In examples: (1) (A) 4 : 41-diaminostilbene-2 : 21-disulphonic acid is tetrazotized and coupled with the o -methanesulphonic acid of 2-aminobenzoic acid, and the product is hydrolysed with caustic soda solution; (B) the disodium salt of 4 : 41-dinitrostilbene-2 : 21-disulphonic acid is refluxed with 2 mols. of 2 : 5-diaminobenzoic acid in aqueous caustic soda solution; (c) the monoazo dyestuff 4-nitro-41-aminostilbene-2 : 21-disulphonic acid --> the o -methanesulphonic acid of 2-aminobenzoic acid (hydrolysed) is similarly condensed with an equimolecular proportion of 2 : 5-diaminobenzoic acid; the product of (A), (B) or (C) is then tetrazotized and coupled with 1-phenyl-3-methyl-5-pyrazolone or its 31-sulphonamido- or 31-nitro-derivative; (2) (A) the monoazo dyestuff of (1) (C) is reduced with dextrose in aqueous caustic soda solution; (B) the disodium salt of 4 : 41-dinitrostilbene-2 : 21-disulphonic acid is heated with an equimolecular proportion of 2 : 5-diaminobenzoic acid in aqueous caustic soda solution and the product is reduced as in (A); the product of (A) or (B) is then tetrazotized and coupled with 3-methyl-5-pyrazolone or 1 - phenyl - or 1 - (41 - hydroxy - 31 - carboxyphenyl) - 3 - methyl - 5 - pyrazolone; (3) the reduction in (2) (A) is effected with a smaller proportion of dextrose, and the product is tetrazotized and coupled with 1-phenyl-3-methyl-5-pyrazolone; (4) the monoazo dyestuff of (1) (C) is diazotized and coupled with 1 - phenyl - 3 - methyl - 5 - pyrazolone and the product is reduced as in (2) (A); (5) the disodium salt of 4 : 41-dinitrostilbene-2 : 21-disulphonic acid is refluxed in aqueous caustic soda solution with the aminoazo dyestuff obtained by reduction of the dyestuff 5-nitro-2-aminobenzoic acid --> 1 - phenyl - 3 - methyl - 5 - pyrazolone; (6) the nitro-disazo dyestuff of (4) is reduced with sodium sulphide to the corresponding aminoazo dyestuff, which is then treated with phosgene; (7) cotton is dyed with the product obtained by tetrazotizing the intermediate of (1) (B) and coupling with 1-phenyl-3-methyl-5-pyrazolone, from a bath containing sodium carbonate and, in the later stages, Glauber salt, and the dyeing is coppered in the same bath by adding a solution of copper tartrate made weakly alkaline with sodium carbonate, yielding red shades.  Specification 455,274 is referred to.  The Specification as open to inspection under Sect. 91 comprises generally the manufacture of polyazo dyestuffs of the stilbene series using at least once as a middle component a 2-aminobenzoic acid, and using any end components.  As additional end components, which preferably couple in o-position to a hydroxy group, are specified compounds of the benzene or naphthalene series, e.g. naphthols or naphtholsulphonic acids, and compounds containing an open chain, e.g. acetoacetic arylides.  This subject-matter does not appear in the Specification as accepted.